Comment by bbayer

I want to learn PCB design, mostly with ARM and ESP based designs. How would I learn basics? I know theory part but I really couldn't figure out why they determine which component and which value they have to use. I mean there are resistors, capacitors all over the place but I really want to learn reason behind it. Also I guess there are some basics related power, battery, UART, USB etc. Is there any source that covers all of these concepts?